Expert: Vehicle emissions, not pesticides, are killing toads

Vehicle emissions and other pollutants are partly to blame for falling amphibian numbers in Bermuda, according to an expert.

Jamie Bacon, a research associate with the Bermuda Zoological Society, told The Royal Gazette that emissions from cars, bikes and trucks were contributing hydrocarbons and metals to the environment and that these pollutants were causing a number of adverse health effects in toads and other wildlife.

Habitat destruction is also having an effect on toad numbers, according to the scientist.

Dr Bacon said there was “no evidence” that pesticides were to blame, as was claimed in a recent newspaper column by activist Tony Brannon.

She and other scientists are involved in a research project, part-funded by Government, which has previously looked at the toxicity of pesticides around ponds but is now focusing on how vehicle emissions and “road run-off” are causing health effects on toads and other species.

She told us in an e-mail: “We have no data to suggest that pesticides are responsible for amphibian declines in Bermuda as we have found no link between pesticides and the effects we have seen, except in two isolated cases on golf courses where unique deformities appeared to be linked to particular pesticides.

“[But] we have put out articles previously on hydrocarbons and metals, which are causing a number of effects in local wildlife including deformities, suppressed immune function, impaired reproduction and endocrine disruption (altered hormone levels).

“They are likely to be causing declines in our toad population. We also have lost one species of whistling frog [in 1994] but we may never know why that species went extinct locally.”

Mr Brannon claimed in his Bermuda Sun column last month that pesticides had caused a “silent health issue” in Bermuda, putting “cancer rates … through the roof”.

He wrote: “If I were the leader of Bermuda, I would immediately ban these lethal pesticides that contribute to causing cancer in humans. Besides humans, bee colony collapse is significant and tree frogs, toads, amphibians are all way down in numbers.”

Asked to comment, Dr Bacon said in her e-mail: “I am disturbed that he is saying pesticides are causing declines in Bermuda’s whistling frogs and amphibians (the only other amphibian is our cane toad).

“We have no evidence for that. Certainly, there could be issues with adult toads going onto golf course fairways or into farm fields that have been recently sprayed. But we have not studied that, so I have no data.”

A Ministry of Health and Environment spokeswoman said a study launched by the Zoological Society and the Department of Environmental Protection in 1995 tested the toxicity of 13 pesticides used on farms and golf courses around ponds.

She said the study — initially called the Amphibian Project — evolved into an ecological risk assessment that had been ongoing since 2000.

The spokeswoman added: “Currently, this research programme is focusing on other pollutants, primarily from vehicle emissions and road run-off, that cause impacts or health effects in toads and other species and is determining how to correct these effects in ponds.”

Dr Bacon said information on the declining toad population was largely anecdotal. “We talk to people who say: 20 years ago, if it was raining, you couldn’t drive on the roads without seeing a toad. Now they hardly see any.

“What I started seeing was a very alarming high incidence of deformities. Our focus now is to identify how we can try to reverse the situation.”

She said it was a shame that vehicle emission controls had yet to be legislated, as reported by this newspaper yesterday, because reducing emissions could potentially help the situation.

“It’s understandable that people are not that worried about toads,” added Dr Bacon. “But we are also finding effects in terrapins and our two species of endemic killifish, which are a protected species. We have two species and two potential subspecies They are being profoundly affected.”

Government has been testing emissions for all vehicles annually for the past five years — but has yet to set any legal limits. A Ministry of Transport spokesman said setting limits was something the Ministry was continuing to review and would “move forward with at the appropriate time”.

A January 2011 report published by the Department of Health and Bermuda Health Council found that the Island’s mortality rate for all cancers was lower than the OECD (Organisation for Economic Co operation and Development) average and on a par with rates in the US.

The Ministry of Health and Environment spokeswoman said Government was reviewing its policies regarding the use of various pesticides but that “extensive literature reviews have found no link between glyphosate [the active ingredient in Roundup and Rodeo pesticides) and cancer”.

She said: “It is understood that all pesticides are to be used only as directed in order to limit potential health risks. Government is (and has been) in the process of reviewing and drafting regulations regarding pesticide usage and it is expected that these will ultimately be implemented.

“Government is not only aware of the environmental risks but is actively funding this research to understand the pollutant sources, which include pesticides.”

The spokeswoman said the Environmental Protection Agency in the US was reviewing glyphosate as a part of a routine re-registration process with an end date of 2015.

“If any new restrictions are published, we will be reviewing those as they become available. The Department of Environmental Protection takes all complaints and concerns related to pesticides used in Bermuda very seriously and is of the mind that any use restrictions or revocations of pesticides must be based on sound scientific information.”

The spokeswoman added: “Revised controls over pesticides importation and the training of local pesticide applicators are already under way through the work of the Department of Environmental Protection and the Department of Health.

“It is expected that the revised laws themselves will be put into place over the next two to three years.”

Dr Bacon said: “A review of the toxicity of glyphosate was done by looking at articles listed in PubMed, a very scientific data base.

“That’s not to say that they are perfect but the peer-review process is a strict one and usually ensures that the science is sound — and substantiated.”

Asked what he based his claims on, Mr Brannon said: “I got a lot of info off the web, off Google and stuff like that. As far as the cancer situation, that was told [to a friend] by a Lahey [Clinic] person.